Job specialization encouraged leisure time, which allowed people to appreciate and develop art, sports, theater, and recreation. Citizens of early cities gained the ability to specialize in their jobs, or to work in certain trades rather than sharing agricultural or other work. Agricultural innovations like irrigation, crop cycling, and harvesting techniques meant that fewer people were needed to work as farmers and laborers. With specialized trades, more citizens in the city could work exclusively in cultural and social trades, developing art and entertainment. Cities became places where cultures developed. These developments pulled new people to cities because the city became the place to learn and experience things that could not be experienced in isolated rural environments.
Innovations since the Industrial Revolution that have contributed to the mechanization of agriculture include refrigeration, mechanical threshers and harvesters, airplanes, electricity, irrigation machines, and the use of computers.
In case of emergencies such as natural disaster or security breaches, the president of the United States have the constitutional right to make a sole decision on dealing wir with it.
